DATA MINING
Desktop Survival Guide by Graham Williams |
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Arrays |
An array is a vector that in addition has attributes
associated with it. Attributes are used in R to record additional
information about an object. Consider the simple example of a sequence
of numbers (which is a simple vector by default):
> seqv <- 1:20 > is.vector(seqv) [1] TRUE > is.array(seqv) [1] FALSE > seqa <- as.array(1:20) > is.array(seqa) [1] TRUE > is.vector(seqa) [1] FALSE > attributes(seqv) NULL > attributes(seqa) $dim [1] 20 > seqv@dim Error: cannot get a slot ("dim") from an object of type "integer" > seqa@dim [1] 20 |